Cameras and other optical devices such as scopes, binoculars, laser transits, and camcorders are often mounted on a tripod or other support by a head that enables panning by rotating about a vertical axis and tilting by rotating about a horizontal axis. Panning and tilting enable a user to search an area for a target or locate a point of interest with an optical device. Typical examples are using a telescope to locate astronomical phenomenon, using a spotting scope or binoculars to locate an animal while hunting or bird watching etc., or using a camera to find and photograph a point of interest.
Conventional tripod heads usually include a base that mounts on the tripod and a platform on which the camera or other optical device mounts. The platform may be independently positioned relative to the base by pivoting about two or three mutually perpendicular axes, which enables flexibility in aiming the optical device. Some tripod heads have a locking mechanism to lock the optical device in a desired position.
One such tripod head is described in U.S. Pat. No. 3,924,828, the head being a pan-tilt tripod head that is capable of panning, tilting, and rolling to either side about three orthogonal axes and has a locking mechanism for all three axes controlled by a single trigger. A cylindrical rotatably mounted trunnion enables the head to pan about one axis, a clamp bracket journalled on the trunnion enables the head to tilt about a second axis, and a head bracket pivotally mounted on the end of the clamp bracket enables the head to roll about a third axis.
U.S. Pat. No. 4,763,151 discloses a universal tripod head that has a base member that mounts on a tripod for pivotal movement about a panning axis and a platform on which a camera may be mounted. Components are provided that enable independent pivotal movement of the platform member about two mutually perpendicular tilting axes. A locking mechanism locks the platform against movement about both of the tilting axes by operation of a single knob.
When a point of interest is found with a conventional tripod head, it may be easily lost if the optical device is bumped or moved when in an unlocked position. Particularly when using a spotting scope for viewing a target at a great distance, even a slight shift of the scope will take the target out of the scope's field of view. The point of interest, whether a landmark or an animal, may be difficult to relocate once lost from the field of view of the optical device. To avoid losing a point of interest, most tripod heads have a lock that holds the tripod head in a desired position. However, just the act of locking the tripod head in a desired position can cause the tripod head to shift out of the desired position. Additionally, locks require time and effort that can cause a viewer to miss a photo opportunity or miss spotting an animal or other object of interest.
Various attempts have been made to provide a tripod head that cures these deficiencies. Once such example is described in U.S. Pat. No. 4,341,452 to Korling, which discloses a camera mount that is independently or simultaneously pivotable about three axes. Pivot assemblies with plastic friction washers enable the camera to be moved from one position to another, yet it will stay in the second position without needs of a locking means. However, the Korling tripod mount requires a bracket specifically designed for hand-held single lens reflex (SLR) cameras. Only hand-held SLR cameras may be properly balanced in the mount. Other optical devices may be imbalanced, causing creep from the position to which the optical device is set.
Therefore, there is a need in the art for a mount for a tripod head which may provide the capability to pan and tilt without requiring a locking mechanism.